Enantioselective 1,3-dipolar cycloaddition of nitrones to methacrolein catalyzed by (η5-C5Me5)M{(R)-Prophos} containing complexes (M = Rh, Ir;: (R)-Prophos=1,2-bis(diphenylphosphino)propane):: On the origin of the enantioselectivity

被引:92
作者
Carmona, D [1 ]
Lamata, MP
Viguri, F
Rodríguez, R
Oro, LA
Lahoz, FJ
Balana, AI
Tejero, T
Merino, P
机构
[1] Univ Zaragoza, CSIC, Inst Ciencia Mat Aragon, Inst Univ Catalisis Homogenea,Dept Quim Inorgan, E-50009 Zaragoza, Spain
[2] Univ Zaragoza, CSIC, Inst Ciencia Mat Aragon, Inst Univ Catalisis Homogenea,Dept Quim Organ, E-50009 Zaragoza, Spain
关键词
D O I
10.1021/ja0539443
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The rhodium and iridium Lewis-acid cations [(eta(5)-C5Me5)M{(R)-Prophos}(H2O)](2+) ((R)-Prophos = 1,2-bis(diphenylphosphino)propane) efficiently catalyze the enantioselective 1,3-dipolar cycloaddition of nitrones to methacrolein. Reactions occur with perfect endo selectivity and with enantiomeric excesses up to 96%. Intermediates [(eta(5)-C5Me5)M{(R)-Prophos}(methacrolein)](SbF6)(2) (M = Rh (3), Ir (4)) have been spectroscopically and crystallographically characterized. The nitrone complexes [(eta(5)-C5Me5)M{(R)-Prophos}-(nitrone)](SbF6)(2) (M = Rh, nitrone = 1-pyrrolidine N-oxide (5), 2,3,4,5,-tetrahydropyridine N-oxicle (6), 3,4-dihydroisoquinoline N-oxide (7); M = Ir, nitrone = 1-pyrrolidine N-oxide (8)) have been isolated and characterized including the X-ray crystal structure of compounds 6 and 8. The equilibrium between methacrolein and nitrone complexes is also studied. [Ir]-adduct complexes are detected by P-31 NMR spectroscopy. A catalytic cycle involving [M]-methacrolein, [M]-nitrone, as well as [M]-adduct species is proposed, the first complex being the true catalyst. The absolute configuration of the adduct 4-methyl-2-N,3-diphenyl-isoxazolidine-4-carbaldehyde (9) was determined through its (S)-(-)-alpha-methylbenzylamine derivative diastereomer. Structural parameters strongly suggest that the disposition of the methacrolein in 3 and 4 is fixed by CH/pi attractive interactions between the pro-S phenyl ring of the Ph2PCH(CH3) moiety of the (R)-Prophos ligand and the CHO aldehyde proton. Proton NMR data indicate that this conformation is maintained in solution. From the structural data and the results of catalysis the origin of the enantioselectivity is discussed.
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页码:13386 / 13398
页数:13
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共 60 条
[51]  
Suezawa H, 2002, EUR J INORG CHEM, P3148
[52]   Ab initio study of Lewis acid catalyzed nitrone cycloaddition to electron deficient alkenes. Does a Lewis acid catalyst change the reaction mechanism? [J].
Tanaka, J ;
Kanemasa, S .
TETRAHEDRON, 2001, 57 (05) :899-905
[53]  
TUFARIELLO JJ, 1984, 1 3 DIPOLAR CYCLOADD, pCH9
[54]   CH/π interaction in the crystal structure of organic compounds.: A database study [J].
Umezawa, Y ;
Tsuboyama, S ;
Honda, K ;
Uzawa, J ;
Nishio, M .
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 1998, 71 (05) :1207-1213
[55]   Nitrones as ligands in complexes of Cu(II), Mn(II), Co(II), Ni(II), Fe(II), and Fe(III) with N-tert-butyl-α-(2-pyridyl)nitrone and 2,5,5-trimethyl-1-pyrroline-N-oxide [J].
Villamena, FA ;
Dickman, MH ;
Crist, DR .
INORGANIC CHEMISTRY, 1998, 37 (07) :1446-1453
[56]   Iron and ruthenium Lewis acid catalyzed asymmetric 1,3-dipolar cycloaddition reactions between nitrones and enals [J].
Viton, F ;
Bernardinelli, G ;
Kündig, EP .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2002, 124 (18) :4968-4969
[57]   PENTAMETHYLCYCLOPENTADIENYL-RHODIUM AND PENTAMETHYLCYCLOPENTADIENYL-IRIDIUM COMPLEXES .12. TRIS(SOLVENT) COMPLEXES AND COMPLEXES OF ETA-6-BENZENE, ETA-6-NAPTHALENE, ETA-6-PHENANTHRENE, ETA-6-INDENE, ETA-6-INDOLE, ETA-6-FLUORENE AND ETA-5-INDENYL AND ETA-5-INDOLYL [J].
WHITE, C ;
THOMPSON, SJ ;
MAITLIS, PM .
JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS, 1977, (17) :1654-1661
[58]   The metal-ligand bifunctional catalysis: A theoretical study on the ruthenium(II)-catalyzed hydrogen transfer between alcohols and carbonyl compounds [J].
Yamakawa, M ;
Ito, H ;
Noyori, R .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2000, 122 (07) :1466-1478
[59]  
Yamakawa M, 2001, ANGEW CHEM INT EDIT, V40, P2818, DOI 10.1002/1521-3773(20010803)40:15<2818::AID-ANIE2818>3.0.CO
[60]  
2-Y